How to instantiate an instance of type represented by type parameter in Scala

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EDIT – apologies, I only just noticed your first error. There is no way of instantiating a T at runtime because the type information is lost when your program is compiled (via type erasure)

You will have to pass in some factory to achieve the construction:

class BalanceActor[T <: Actor](val fac: () => T) extends Actor {
  val workers: Int = 10

  private lazy val actors = new Array[T](workers)

  override def start() = {
    for (i <- 0 to (workers - 1)) {
      actors(i) = fac() //use the factory method to instantiate a T
      actors(i).start
    }
    super.start()
  }
}

This might be used with some actor CalcActor as follows:

val ba = new BalanceActor[CalcActor]( { () => new CalcActor } )
ba.start

As an aside: you can use until instead of to:

val size = 10
0 until size //is equivalent to:
0 to (size -1)

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